The World Outdoors: City lives up to cardinal capital tag

This week I was standing under the sun in the middle of one of London’s Environmentally Significant Areas surrounded by northern cardinals making their distinctive chip calls.

Many other birders would have had a similar experience. London birder Bob McGee posted an observation on a local bird alert. The 12 cardinals he counted at one time was a record for his yard.

London has long been referred to as the “cardinal capital of Canada.” There have frequently been more of these beautiful birds counted on London Christmas Bird Counts than anywhere else in the nation.

A red male against a white blanket of snow is a brilliant sight that never bores me. The female with more muted plumage has been likened to a Burberry scarf. Because of their beauty and ubiquity, because they are easily identified, and because they can be seen in urban, suburban, and rural areas through every season, cardinals are among those birds that turn non-birders into birders.

Cardinals are among the few North American bird species that don’t migrate. They live across southern Ontario and Quebec, the Eastern U.S., and – perhaps surprisingly – Mexico.

How can they do so well here, even in a snowy winter? For starters they have a physiology that has adapted to the climate and they have many layers of feathers that will be puffed up for insulation. They will also avoid the wind, staying low in branches and brambles and foraging at or near the ground.

A cardinal’s diet also allows them to exploit a wide variety of food sources. This is a life and death issue. Birds need to store fat that they will then burn on particularly cold days and nights.

Through the spring, summer, and fall, cardinals will eat insects but these food sources are scarce now. In the winter they are able to eat fruit such as dogwood, wild grape, hackberry, buckthorn, and sumac as well as seeds.

It is the ability of other winter birds to take advantage of fruits, natural seed sources and backyard feeders that allows them, like our cardinals, to cope with our winters. Other wintertime fruit-eaters include cedar waxwings and American robins,

Some of our other winter birds are not fruit eaters. The mourning dove might very occasionally eat berries, but the vast majority of its diet is seed-based. Other winter seed eaters include blue jays, juncos, tree sparrows and goldfinches.

Some people will put oranges out for orioles in the spring, but fruit can also be included at a backyard feeder in the winter. Chopped raisins soaked in water can be put out with the always popular black-oil sunflower seed, shelled peanuts, suet, niger seed, cracked corn, or a good quality mixed seed.

The free Nature in the City speaker series continues Tuesday with Western University’s Dr. Keith Hobson presenting an illustrated talk about new technologies being used to track migrating birds and other animals. This science, known as biogeochemistry, links to climate change and conservation. The speaker series is co-sponsored by Nature London and the London Public Library. Talks starts at 7 p.m. at the Central Library’s Wolf Performance Hall at 251 Dundas St. See naturelondon.com

Dr. Keith Hobson is also one of the co-editors-in-chief of Avian Conservation & Ecology, an open-access online scientific journal published by the Society of Canadian Ornithologists and Bird Studies Canada. The most recent issue of this journal was published earlier this month and includes interesting articles such as the reliability of eBird data from citizen scientists as a predictor of biodiversity in urban green spaces. To read the original research or to subscribe to this free periodical, navigate to ace-eco.org.

The strong links between bird science and broader environmental issues are readily apparent in the just-published research led by Yanju Ma, a scientist at Western University’s Advanced Facility for Avian Research. Through a controlled study of yellow-rumped warblers, she determined that dietary exposure to methylmercury significantly affects the flight endurance of migratory songbirds. The study is published in the journal Environmental Pollution.